This trifecta of tight credit, low inventory, and high demand has created a highly segmented market, one that favors the cash-heavy and the affluent. Buyers like Ellen can’t buy a place without selling their apartments first—but if they sell, there’s no guarantee they’ll be able to close on a place they like, given the market frenzy. So holding on makes sense. First-timers like Daniel can’t get traction, because they need mortgages in a marketplace teeming with all-cash buyers. And then there are people like broker Donald Brennan’s clients, a couple who sold their two-bedroom co-op two years ago to free up a massive down payment for a townhouse. But Brooklyn townhouses have seen their prices go skyward, too. The couple ended up having to settle for a condo.

Prospective buyers are moving further and further out in search of an affordable property, but really, it’s getting expensive everywhere. In Crown Heights, the median price of two-bedrooms listed on Streeteasy.com is $425,000, out of reach for many in a city with a median household income of $51,270. In one sense, real estate here isn’t unaffordable, since clearly there are buyers out there, says the economist Chris Mayer, who teaches at Columbia University’s business school, but it has become “unaffordable to people who’ve lived here a long time.” They’re competing against high-net-worth Americans (both locals and pied-à-terre types) as well as foreign investors able to purchase mortgage-free. Brokers talk of an uptick in European, Brazilian, and Chinese clients.

New Yorkers have been kvetching about the disappearance of old New York since there was a New York. But the real-estate market of this moment suggests that Mayor Bloomberg’s description of the city as a luxury product is becoming more and more true, especially in its most expensive provinces. Just as in the London neighborhood of Belgravia, many of New York’s most expensive apartments sit empty for much of the year, their superrich owners using them as vacation properties and safe investments instead of actual homes.

When so-called up-and-coming Bed-Stuy and Crown Heights are commanding mid-six figures for properties, it hardly makes sense to talk about gentrification ­anymore—it’s a new city, and in a lot of neighborhoods, even the gentry can’t find a place to live.